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名稱Title
2018天文年會
國立金門大學
5月18日至20日

論文摘要

The most accurate luminosity function of local infrared galaxies based on the AKARI all sky survey

[ Oral ]

Ece Kilerci Eser, and Tomotsugu Goto (NTHU)

Local infrared (IR) luminosity functions (LFs) are necessary benchmarks for high-redshift IR galaxy evolution studies. Any accurate IR LF evolution studies require accordingly accurate local IR LFs. We constructed IR galaxy LFs at $z \leq 0.3$ from \textit{AKARI} space telescope, which performed an all-sky survey in six IR bands (9, 18, 65, 90, 140 and 160 $\mu$m) with 3-10 times better sensitivity than its precursor IRAS. Availability of 160 $\mu$m filter is critically important in accurately measuring total IR luminosity of galaxies, covering across the peak of the dust emission. By combining mid-IR data from \textit{WISE}, and spectroscpic redshifts from SDSS DR13, 6dFGS, and 2MRS, we created a sample of 15,638 local IR galaxies with spectroscopic redshifts, i.e., by a factor of 20 larger than the well-cited previous work from IRAS, let alone IRAS limit to $<$100 $\mu$m. After carefully correcting for volume effects in both IR and optical, the obtained IR LFs agree well with previous studies, but comes with much smaller errors. Especially both faint- and bright-ends of the LFs are better-determined, due to much larger size of the spectroscpic redshifts and the IR photometry. Measured local IR luminosity density is $\Omega_{IR}= 1.19\pm0.05 \times 10^{8} L_{\odot}$ Mpc$^{-3}$. The contributions from luminous infrared galaxies and ultra luminous infrared galaxies to $\Omega_{IR}$ are very small, 9.3 per cent and 0.9 per cent, respectively. There exists no future all sky survey in far-infrared wavelengths in the foreseeable future. The IR LFs obtained in this work will therefore remain an important benchmark for high-redshift studies for decades.